Mary M. Gallenberg, MD, is an assistant professor in the Department of Obstetrics and Gynecology at the Mayo Clinic College of Medicine.

Q:How often should I be tested for STDs if I'm sexually active?

A:Get tested immediately if your partner has been diagnosed with a sexually transmitted disease (STD) or if you: Have an unusual discharge from your genitals Feel burning when you urinate Experience genital itching See one or more sores in your genital area

If you're age 25 or under, get tested once a year because you're at a higher risk for contracting STDs than older adults. If you're over 25 and have a new sexual partner or multiple partners, you should also get tested annually.

Q:Which STD tests should I get during my annual visit to the gynecologist?

A:If you are sexually active and age 25 or younger, or any age with a new partner, you should be screened annually for chlamydia and gonorrhea, and undergo a Pap test to detect precancers of the cervix caused by human papillomavirus (HPV). If you've had sex without a condom, have new or multiple partners, or you know you have another STD, you should also get tested for HIV, syphilis, and hepatitis B.

Doctors don't automatically screen for STDs, however, so discuss your recent sexual history and practices to determine which tests you need.

Q:What's the best way to ask my partner about his or her sexual health?

A:The best time, place, and circumstance varies from couple to couple. But it's best to have a straightforward, truthful discussion about previous or existing sexually transmitted diseases and about using protection before having sex.

Q:What if I'm too embarrassed or scared to tell my sex partner that I have an STD?

A:Most people have hesitations about sharing this very private information, but it's necessary for your own protection and for your partner's tooand using protection is a must. Familiarize yourself with recent, accurate information about the infection you have and how it's spread so that you can answer any questions from your partner.

[ pagebreak ] Q:Can I find out whether I have HIV without getting a blood test?

A:No. You need to have a blood test to detect the presence of antibodies to the HIV virus.

Q: Can I get HIV from giving or receiving oral sex?

A:It's relatively rare, but there's a small risk of contracting HIV through unprotected oral sex. The virus can be transmitted through the mouth cuts and sores you get from routine activities such as eating hard foods, brushing your teeth, or chewing gum.

Q:Does having another STD increase my risk of contracting HIV?

A:Yes, having another STD may cause inflammation of the genital tract tissues, which can weaken the body's ability to fight off HIV.

Q:Does using latex condoms reduce the risk of all sexually transmitted diseases and infections?

A:You can dramatically reduce your risk of contracting or spreading STDs if you use a latex condom correctly every time you have vaginal, oral, or anal sex. Condoms are most effective at stopping infections present in vaginal fluids and semen such as HIV, gonorrhea, chlamydia, and trichomoniasis, and less successful in stopping HPV, genital herpes, or syphilisinfections spread through skin-to-skin contact.

Q:The condom broke! Is there anything I can do now to cut my risk of contracting an STD?

A:Postexposure prophylaxis (PEP), a short course of drugs, can prevent HIV infection if you take it within about 72 hours of the condom breaking. However, this treatment is hard to find unless you're in the health-care or law-enforcement field. If you plan to become sexually active with someone who has HIV or AIDS, find a PEP source beforehand.

[ pagebreak ] Q:I have genital herpes. How can I avoid spreading it to my partner?

A:While there is no way to completely eliminate spreading herpes to your partner, you can decrease your risk significantly by using a condom 100% of the time, taking antiviral medications, and avoiding sexual contact until sores from an outbreak are completely healed.

Q:How soon after a herpes outbreak ends can I have sex?

A:Avoid sexual contact until your lesions have healed completely. Even without visible lesions, however, you can shed the virus and infect your partnerso use condoms 100% of the time.

Q:I was just diagnosed with HPV. Does that mean I'll eventually develop cervical cancer?

A:Not necessarily. There are more than 100 strains of HPV, and only about 13 are linked to cancers of the cervixalthough other types may be associated with genital warts and abnormal Pap smears. There is no cure for HPV, but the majority of women diagnosed with both high- and low-risk types will build up enough virus-fighting antibodies to clear the HPV from their systems. Regular Pap smears are the best way to make sure you that you never develop cervical cancer.

Q:I was diagnosed with HPV 10 years ago. Do I have to tell my new partner about it?

A:If your Pap smears have been normal on multiple occasions, you have probably cleared your HPV infection. But there is a small chance you can still transmit HPV to your partner.

Q:How do I know if I have pelvic inflammatory disease (PID)? Is ittreatable?

A:PID symptoms include fever, abdominal pain, and unusual vaginal or cervical discharge. You may also feel tenderness in your uterus during a pelvic exam. If your doctor suspects you have PID, he or she will likely test you for gonorrhea and syphilis, which lead to PID when they go untreated. He or she may also perform a pelvic ultrasound to see if your fallopian tubes are swollen or if you have an abscess.

PID can be treated with antibiotics. See your doctor immediately if you think you have this disease as it can cause infertility if left unchecked.

[ pagebreak ] Q:Can I pass a yeast infection on to my partner by having intercourse or receiving oral sex?

A:Yes, you can. If you have a yeast infection, it's best to abstain from sex until it's healed; use condoms for a while afterward. See a doctor if you experience recurrent yeast infections.

Q:Is bacterial vaginosis sexually transmitted?

A:Yes, bacterial vaginosis can be sexually transmitted. But it can also occur in women who have never been sexually active, so it's not always a sexually transmitted disease.

Q:Which kinds of hepatitis are sexually transmitted and what's the best way to prevent it?

A:Hepatitis A, B, and Cviruses that cause diseases of the livercan be spread through sex. You can be vaccinated against hepatitis A and B. Condoms offer little protection from hepatitis A but do help stop the transmission of B and C.

Q:Which sexually transmitted infections don't have symptoms?

A:Women can have gonorrhea, chlamydia, hepatitis, HIV, and syphilis without having any obvious symptoms. Routine testing is the best way to detect these STDs.

Q:Are urinary tract infections sexually transmitted?

A:Technically speaking, no, but sex can result in a bladder infection. Here's how: Most urinary tract infections are caused by E. coli, a bacterium found in stool. Fecal bacteria may colonize the skin of the perianal area, vulva, and urethra. Thrusting against the urethra during intercourse may move bacteria from the urethra to the bladder, resulting in a bladder infection. This has been called honeymoon cystitis.

Q:I have a greenish yellow, frothy discharge. Is this a symptom of an STD?

A:It may be a symptom of trichomoniasis, gonorrhea, chlamydia, or bacterial vaginosis. See your health-care provider for an accurate diagnosis.